Public Function XDLookup(Expression As String, Domain As String, Optional _
  DBPfad, Optional Criteria) As Variant
    Dim strSQLDF As String
    On Error GoTo Err_XDLookup
    strSQLDF = "SELECT " & Expression & " FROM " & Domain
    If (Not IsMissing(DBPfad)) Then
    If (Len(Nz(DBPfad, "")) > 0) Then strSQLDF = strSQLDF & " IN " & Chr(34) _
      & DBPfad & Chr(34)
    End If
    If (Not IsMissing(Criteria)) Then
    If (Len(Nz(Criteria, "")) > 0) Then strSQLDF = strSQLDF & " WHERE " & _
      Criteria
    End If
    strSQLDF = strSQLDF & ";"
    XDLookup = DBEngine(0)(0).OpenRecordset(strSQLDF, dbOpenForwardOnly)(0)
    Exit Function
Err_XDLookup:
    XDLookup = Null
End Function

Dim Vorhanden As Variant
If  Vorhanden <> Null Then
Vorhanden = XDLookup(" & NewTechField.Value & ", Technology)

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